Fluid-flow control valve



Feb. 4, 1969 F. PAWLING 3,425,450

FLUID-FLOW CONTROL VALVE I Filed Dec. 28, 1966 INVENTOR. FRANK PAWLING, Deceased, By RUTH CORFE PAWLING, Execuirix MMNM ATTORNEYS United States Patent company Filed Dec. 28, 1966, Ser. No. 605,510 Claims priority, application Great Britain, Jan. 13, 1966,

1,7 66 US. Cl. 137630.22 Int. Cl. F16k 11/04 2 Claims ABSTRACT OF THE DISCLOSURE A fluid-flow control valve includes two two-position valve elements one within the other in a common housing, itself having one inlet and three outlets. When both valve elements are in their first positions, the inlet is in communication with a first of said outlets while the other outlets communicate with each other through the interior of the outer valve element. When the valve elements are moved to their second positions, the first outlet is isolated from the inlet, and the inlet is placed instead in communication with the second outlet, while the second outlet is isolated from the third outlet. Resilient means are provided for urging the valve elements towards their first positions, while fluid-pressure-operable actuator means are provided for moving the valve elements from their first to their second positions.

Field of the invention This invention relates to fluid-flow control valves.

Summary of the invention The present invention provides a fluid-flow control valve including a housing forming a first chamber having an inlet, a second chamber extending from the first chamber and having a first outlet, and a third chamber extending from the first chamber and having a second outlet, a first valve member movable in the first chamber from a first position to a second position, the first position being one in which the first valve member isolates the third chamber from the first chamber and the first chamber is open to the second chamber, the second position being one in which the first valve member isolates the second chamber from the first chamber and the first chamber is open to the third chamber, the first valve member having a passage extending from a portion of the first valve member adjacent the third chamber to a third outlet, a second valve member located in the passage and movable relative to the first valve member from a first position in which the third chamber is open through the passage to the third outlet to a second position in which the passage is closed by the second valve member to isolate the third chamber from the third outlet, resilient means urging the first and second valve members towards their respective first positions, and actuating means operable to first move the second valve member from its first position to its second position and then to move the first and second valve members simultaneously such that the second valve member remains in its second position and the first valve member moves from its first position to its second position.

The actuating means may be fluid-pressure-operable and comprise a piston displaceable in a cylinder also for-med in said housing.

3,425,450 Patented Feb. 4, 1969 'ice Brief description of the drawing The accompanying drawing is a view which shows diagrammatically in cross-section a fluid-flow control valve in accordance with the invention.

Description of the preferred embodiment With reference to the drawing a fluid-flow control valve includes a housing 1 forming a first chamber 2 having an inlet 3, a second chamber 4 extending from the first chamber 2 and having a first outlet 5, and a third chamber 6 extending from the first chamber 2 and having a second outlet 7.

A first valve member '8 is slidably mounted in the housing 1 and extends into the second and first chambers 4, 2. The first valve member 8 has a head portion 9 in the first chamber 2, and is slidable from a first position to a second position. In the first position (as shown in the drawing), a frusto-conical surface '11 of the head portion 9 engages a valve seat 12 formed by a shoulder in the housing 1 to isolate the third chamber 6 from the first chamber 2, the first chamber 2 being open to the second chamber '4. In the second position, a frusto-conical surface 13 of the head portion 9 engages a valve seat 14 formed by another shoulder in the housing 1 to isolate the second chamber 4 from the first chamber 2, the first chamber 2 then being open to the third chamber 6.

The first valve member 8 has a passage 15 extending from the leading end of the head portion 9 adjacent the third chamber 6 to a fourth chamber 16 having a third outlet 17. A second valve member 18, of poppet type, is located in the passage 15 and is movable relative to the first valve member 8 from a first position (as shown in the drawing), in which the third chamber 6 isopen through the passage 15 and fourth chamber 16 to the third outlet 17, to a second position in which the passage 15 is closed by the engagement of a frusto-conical surface 19 of the second valve member 18 with a valve seat 21 formed by a counter-bored portion in the first valve member 8 to isolate the third chamber 6 from the fourth chamber 16 and third outlet 17.

Resilient means in the form of a mechanical coil spring 23 is located in the fourth chamber 16, and acts between the housing 1 and the first and second valve members 8, 18 to urge them to their respective first positions, as shown in the drawing.

An actuating means is provided for the control valve and includes a piston 24 slidably mounted in a fifth chamber 25 extending from the third chamber 6 in the housing 1, the housing also having a passage 26 which communicates with the fifth chamber 25. The actuating means is operated by fluid under pressure supplied to the fifth chamber 25 through the passage 26. The piston 24 is actuated by the fluid under pressure to first move the second valve member 18 from its first position to its second position and then to move the first and second valve members 8 and 18 simultaneously such that the second valve member 18 remains in its second position and the first valve member 8 moves from its first position to its second position.

Thus, in use, fluid under pressure applied to the inlet 3 can be caused to flow either to the first outlet 5 or to the second outlet 7. When the second outlet 7 is not in communication with the inlet 3, it is in communication with the third outlet 17, which may be connected to a fluid return line or to atmosphere. The inlet 3 can never communicate with the third outlet 17. The fluid pressure in the inlet 3 may have a sufiiciently high value such that, when the inlet 3 is in communication with the secnd outlet 7, the fluid pressure in the third chamber 6 holds the first and second valve members 8 and 18 in their second positions when pressure in the chamber 25 is lost.

What is claimed is:

1. A fluid-flow control valve wherein the improvement comprises in combination: a housing (1) forming a first chamber (2) having an inlet (3), a second chamber (4) extending from the first chamber and having a first outlet (5), and a third chamber (6) extending from the first chamber and having a second outlet (7), a first valve member (8) movable in the first chamber from a first position to a second position, the first position being one in which the first valve member isolates the third chamber from the first chamber and the first chamber is open to the second chamber, the second position being one in which the first valve member isolates the second chamber from the first chamber and the first chamber is open to the third chamber, the first valve member having a passage extending from a portion of the first valve member adjacent the third chamber to a third outlet (17), a second valve member (18) located in the passage and movable relative to the first valve member from a first position, in which the third chamber is open through the passage to the third outlet, to a second position in which the passage is closed by the second valve member to isolate the third chamber from the third outlet, resilient means (23) urging the first and second valve members towards their respective first positions, and actuating means (24), (25) operable to first move the second valve member from its first position to its second position and then to move the first and second valve members simultaneously such that the second valve member remains in its second position and the first valve member moves from its first position to its second position.

2. A fluid-flow control valve as claimed in claim 1, wherein said actuating means is fiuid-pressure-operable and comprises a piston (24) displaceable in a cylinder (25) also formed in said housing (1).

References Cited UNITED STATES PATENTS 2,905,487 9/1959 Schifter l37-630.22 3,143,143 8/1964 Taylor et al. 137-629 3,254,677 6/1966 Wakeman 137630.22

LEONARD D. CHRISTIAN, Primary Examiner. 

